The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

Lightning and Rainbow in Desert Monsoon Thunderstorm

The photo above showing a desert monsoon thunderstorm
pushing off to the east of Catalina, Arizona was taken on the evening of August
5, 2012. A jagged cloud-to-groundlightning bolt dominates the scene while the
gentle arc of a rainbow adds colorful accents. It's not the shield of rain and
dust that paint this rainbow bow in shades of red, orange and yellow but rather
the fact that the bow formed close to sunset. Longer path lengths of sunlight
when the Sun lies near or below the horizon are responsible for reddening
sunsets and rainbows alike. Note that rainbows only occur opposite the Sun
(antisolar point) -- directly behind the camera.